The only thing that comes to mind with regards to oxygen supplementation would be a respiratory therapy equation regarded to as the A-a gradient, which is the following:

PAO2 = FIO2(PB-47) - 1.2(PaCO2), with Fio2 being 21% (the amount of oxygen in the air we breathe normally), and PaCO2 ranging, being the amount of carbon dioxide in the blood. PB is barometric pressure, which ranges depending on where you live. 47 is a constant and I can't remember why lol.

This looks at the oxygen content of the alveoli in the lungs and compared it to the oxygen content in arterial blood. The higher the gradient the higher the O2 content. Now I'm not going to delve too much into the science behind this, but the only reasonable application that would actually make any sense would be the body's ability to oxygenate blood is harder the higher you are above sea level... however compensation for this occurs over the course of a few days. If someone like myself, from Indiana, who is pretty close to sealevel were to travel to Mile High Stadium and stayed for a week, I would probably start getting some headaches within 2-3 days because my CO2 would increase because the elevation makes it harder for circulating blood to pick up oxygen. After a few days the body naturally balances this out. Now if I were to return to Indiana, for about a day or two (about the same amount of time it takes to compensate for being at higher elevation) I would actually be able to OVER saturate my blood with oxygen... but again this would be compensated rather quickly. Now I'm not sure how this would impact training. You would probably have some greater endurance in the long run, but none of this has anything to do with muscle glycogen stores. You would be able to supply oxygen faster and more efficiently to muscles/areas requiring more blood/O2 and be able to get rid of CO2 quicker (possibly faster recovery) but other than that I don't see any benefit. It would most likely be more beneficial to have an increase of packed RBCs transfused into yourself before an event than anything else. You can read about olympians doing this. Having blood drawn off, giving the body a chance to regen fresh cells, and then transfusing that blood back into their bodies so they have more hemaglobin so they can have a higher capacity to carry oxygen.

But I only see the benefits here for endurance/aerobic training rather than anaerobic weight training.

That was in Laymans terms. Hope it made sense. I'm not good going from science > laymans lol.

there was a **** thread with some sort of oxygen canisters. 3L of O2 for like 15 bucks or something.

and i can tell you from my recent experiences working in pulmonary rehab, those peoples lungs are absolutely destroyed from smoking and other factors. but increasing their O2 beyond what they need wont help their endurance working out or doing cardio. they can have a saturation in the high 80's but cant tell a difference between that and mid 90's when their O2 is turned up higher. but to each their own